1 /* Parse expressions for GDB.
2 Copyright (C) 1986, 89, 90, 91, 94, 1998 Free Software Foundation, Inc.
3 Modified from expread.y by the Department of Computer Science at the
4 State University of New York at Buffalo, 1991.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
22 /* Parse an expression from text in a string,
23 and return the result as a struct expression pointer.
24 That structure contains arithmetic operations in reverse polish,
25 with constants represented by operations that are followed by special data.
26 See expression.h for the details of the format.
27 What is important here is that it can be built up sequentially
28 during the process of parsing; the lower levels of the tree always
29 come first in the result. */
32 #include "gdb_string.h"
36 #include "expression.h"
40 #include "parser-defs.h"
42 #include "symfile.h" /* for overlay functions */
44 /* Global variables declared in parser-defs.h (and commented there). */
45 struct expression
*expout
;
48 struct block
*expression_context_block
;
49 struct block
*innermost_block
;
51 union type_stack_elt
*type_stack
;
52 int type_stack_depth
, type_stack_size
;
58 #ifdef MAINTENANCE_CMDS
59 static int expressiondebug
= 0;
62 extern int hp_som_som_object_present
;
65 free_funcalls
PARAMS ((void));
68 prefixify_expression
PARAMS ((struct expression
*));
71 prefixify_subexp
PARAMS ((struct expression
*, struct expression
*, int, int));
73 /* Data structure for saving values of arglist_len for function calls whose
74 arguments contain other function calls. */
82 static struct funcall
*funcall_chain
;
84 /* Assign machine-independent names to certain registers
85 (unless overridden by the REGISTER_NAMES table) */
88 unsigned num_std_regs
= 0;
89 struct std_regs std_regs
[1];
91 struct std_regs std_regs
[] = {
108 unsigned num_std_regs
= (sizeof std_regs
/ sizeof std_regs
[0]);
112 /* The generic method for targets to specify how their registers are
113 named. The mapping can be derived from three sources:
114 REGISTER_NAME; std_regs; or a target specific alias hook. */
117 target_map_name_to_register (str
, len
)
123 /* First try target specific aliases. We try these first because on some
124 systems standard names can be context dependent (eg. $pc on a
125 multiprocessor can be could be any of several PCs). */
126 #ifdef REGISTER_NAME_ALIAS_HOOK
127 i
= REGISTER_NAME_ALIAS_HOOK (str
, len
);
132 /* Search architectural register name space. */
133 for (i
= 0; i
< NUM_REGS
; i
++)
134 if (REGISTER_NAME (i
) && len
== strlen (REGISTER_NAME (i
))
135 && STREQN (str
, REGISTER_NAME (i
), len
))
140 /* Try standard aliases */
141 for (i
= 0; i
< num_std_regs
; i
++)
142 if (std_regs
[i
].name
&& len
== strlen (std_regs
[i
].name
)
143 && STREQN (str
, std_regs
[i
].name
, len
))
145 return std_regs
[i
].regnum
;
151 /* Begin counting arguments for a function call,
152 saving the data about any containing call. */
157 register struct funcall
*new;
159 new = (struct funcall
*) xmalloc (sizeof (struct funcall
));
160 new->next
= funcall_chain
;
161 new->arglist_len
= arglist_len
;
166 /* Return the number of arguments in a function call just terminated,
167 and restore the data for the containing function call. */
172 register int val
= arglist_len
;
173 register struct funcall
*call
= funcall_chain
;
174 funcall_chain
= call
->next
;
175 arglist_len
= call
->arglist_len
;
180 /* Free everything in the funcall chain.
181 Used when there is an error inside parsing. */
186 register struct funcall
*call
, *next
;
188 for (call
= funcall_chain
; call
; call
= next
)
195 /* This page contains the functions for adding data to the struct expression
196 being constructed. */
198 /* Add one element to the end of the expression. */
200 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
201 a register through here */
204 write_exp_elt (expelt
)
205 union exp_element expelt
;
207 if (expout_ptr
>= expout_size
)
210 expout
= (struct expression
*)
211 xrealloc ((char *) expout
, sizeof (struct expression
)
212 + EXP_ELEM_TO_BYTES (expout_size
));
214 expout
->elts
[expout_ptr
++] = expelt
;
218 write_exp_elt_opcode (expelt
)
219 enum exp_opcode expelt
;
221 union exp_element tmp
;
229 write_exp_elt_sym (expelt
)
230 struct symbol
*expelt
;
232 union exp_element tmp
;
240 write_exp_elt_block (b
)
243 union exp_element tmp
;
249 write_exp_elt_longcst (expelt
)
252 union exp_element tmp
;
254 tmp
.longconst
= expelt
;
260 write_exp_elt_dblcst (expelt
)
263 union exp_element tmp
;
265 tmp
.doubleconst
= expelt
;
271 write_exp_elt_type (expelt
)
274 union exp_element tmp
;
282 write_exp_elt_intern (expelt
)
283 struct internalvar
*expelt
;
285 union exp_element tmp
;
287 tmp
.internalvar
= expelt
;
292 /* Add a string constant to the end of the expression.
294 String constants are stored by first writing an expression element
295 that contains the length of the string, then stuffing the string
296 constant itself into however many expression elements are needed
297 to hold it, and then writing another expression element that contains
298 the length of the string. I.E. an expression element at each end of
299 the string records the string length, so you can skip over the
300 expression elements containing the actual string bytes from either
301 end of the string. Note that this also allows gdb to handle
302 strings with embedded null bytes, as is required for some languages.
304 Don't be fooled by the fact that the string is null byte terminated,
305 this is strictly for the convenience of debugging gdb itself. Gdb
306 Gdb does not depend up the string being null terminated, since the
307 actual length is recorded in expression elements at each end of the
308 string. The null byte is taken into consideration when computing how
309 many expression elements are required to hold the string constant, of
314 write_exp_string (str
)
317 register int len
= str
.length
;
319 register char *strdata
;
321 /* Compute the number of expression elements required to hold the string
322 (including a null byte terminator), along with one expression element
323 at each end to record the actual string length (not including the
324 null byte terminator). */
326 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
+ 1);
328 /* Ensure that we have enough available expression elements to store
331 if ((expout_ptr
+ lenelt
) >= expout_size
)
333 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
334 expout
= (struct expression
*)
335 xrealloc ((char *) expout
, (sizeof (struct expression
)
336 + EXP_ELEM_TO_BYTES (expout_size
)));
339 /* Write the leading length expression element (which advances the current
340 expression element index), then write the string constant followed by a
341 terminating null byte, and then write the trailing length expression
344 write_exp_elt_longcst ((LONGEST
) len
);
345 strdata
= (char *) &expout
->elts
[expout_ptr
];
346 memcpy (strdata
, str
.ptr
, len
);
347 *(strdata
+ len
) = '\0';
348 expout_ptr
+= lenelt
- 2;
349 write_exp_elt_longcst ((LONGEST
) len
);
352 /* Add a bitstring constant to the end of the expression.
354 Bitstring constants are stored by first writing an expression element
355 that contains the length of the bitstring (in bits), then stuffing the
356 bitstring constant itself into however many expression elements are
357 needed to hold it, and then writing another expression element that
358 contains the length of the bitstring. I.E. an expression element at
359 each end of the bitstring records the bitstring length, so you can skip
360 over the expression elements containing the actual bitstring bytes from
361 either end of the bitstring. */
364 write_exp_bitstring (str
)
367 register int bits
= str
.length
; /* length in bits */
368 register int len
= (bits
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
370 register char *strdata
;
372 /* Compute the number of expression elements required to hold the bitstring,
373 along with one expression element at each end to record the actual
374 bitstring length in bits. */
376 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
);
378 /* Ensure that we have enough available expression elements to store
381 if ((expout_ptr
+ lenelt
) >= expout_size
)
383 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
384 expout
= (struct expression
*)
385 xrealloc ((char *) expout
, (sizeof (struct expression
)
386 + EXP_ELEM_TO_BYTES (expout_size
)));
389 /* Write the leading length expression element (which advances the current
390 expression element index), then write the bitstring constant, and then
391 write the trailing length expression element. */
393 write_exp_elt_longcst ((LONGEST
) bits
);
394 strdata
= (char *) &expout
->elts
[expout_ptr
];
395 memcpy (strdata
, str
.ptr
, len
);
396 expout_ptr
+= lenelt
- 2;
397 write_exp_elt_longcst ((LONGEST
) bits
);
400 /* Add the appropriate elements for a minimal symbol to the end of
401 the expression. The rationale behind passing in text_symbol_type and
402 data_symbol_type was so that Modula-2 could pass in WORD for
403 data_symbol_type. Perhaps it still is useful to have those types vary
404 based on the language, but they no longer have names like "int", so
405 the initial rationale is gone. */
407 static struct type
*msym_text_symbol_type
;
408 static struct type
*msym_data_symbol_type
;
409 static struct type
*msym_unknown_symbol_type
;
412 write_exp_msymbol (msymbol
, text_symbol_type
, data_symbol_type
)
413 struct minimal_symbol
*msymbol
;
414 struct type
*text_symbol_type
;
415 struct type
*data_symbol_type
;
419 write_exp_elt_opcode (OP_LONG
);
420 write_exp_elt_type (lookup_pointer_type (builtin_type_void
));
422 addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
423 if (overlay_debugging
)
424 addr
= symbol_overlayed_address (addr
, SYMBOL_BFD_SECTION (msymbol
));
425 write_exp_elt_longcst ((LONGEST
) addr
);
427 write_exp_elt_opcode (OP_LONG
);
429 write_exp_elt_opcode (UNOP_MEMVAL
);
430 switch (msymbol
-> type
)
434 case mst_solib_trampoline
:
435 write_exp_elt_type (msym_text_symbol_type
);
442 write_exp_elt_type (msym_data_symbol_type
);
446 write_exp_elt_type (msym_unknown_symbol_type
);
449 write_exp_elt_opcode (UNOP_MEMVAL
);
452 /* Recognize tokens that start with '$'. These include:
454 $regname A native register name or a "standard
457 $variable A convenience variable with a name chosen
460 $digits Value history with index <digits>, starting
461 from the first value which has index 1.
463 $$digits Value history with index <digits> relative
464 to the last value. I.E. $$0 is the last
465 value, $$1 is the one previous to that, $$2
466 is the one previous to $$1, etc.
468 $ | $0 | $$0 The last value in the value history.
470 $$ An abbreviation for the second to the last
471 value in the value history, I.E. $$1
476 write_dollar_variable (str
)
479 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
480 and $$digits (equivalent to $<-digits> if you could type that). */
482 struct symbol
* sym
= NULL
;
483 struct minimal_symbol
* msym
= NULL
;
487 /* Double dollar means negate the number and add -1 as well.
488 Thus $$ alone means -1. */
489 if (str
.length
>= 2 && str
.ptr
[1] == '$')
496 /* Just dollars (one or two) */
500 /* Is the rest of the token digits? */
501 for (; i
< str
.length
; i
++)
502 if (!(str
.ptr
[i
] >= '0' && str
.ptr
[i
] <= '9'))
506 i
= atoi (str
.ptr
+ 1 + negate
);
512 /* Handle tokens that refer to machine registers:
513 $ followed by a register name. */
514 i
= target_map_name_to_register( str
.ptr
+ 1, str
.length
- 1 );
516 goto handle_register
;
518 /* On HP-UX, certain system routines (millicode) have names beginning
519 with $ or $$, e.g. $$dyncall, which handles inter-space procedure
520 calls on PA-RISC. Check for those, first. */
522 sym
= lookup_symbol (copy_name (str
), (struct block
*) NULL
,
523 VAR_NAMESPACE
, (int *) NULL
, (struct symtab
**) NULL
);
526 write_exp_elt_opcode (OP_VAR_VALUE
);
527 write_exp_elt_block (block_found
); /* set by lookup_symbol */
528 write_exp_elt_sym (sym
);
529 write_exp_elt_opcode (OP_VAR_VALUE
);
532 msym
= lookup_minimal_symbol (copy_name (str
), NULL
, NULL
);
535 write_exp_msymbol (msym
,
536 lookup_function_type (builtin_type_int
),
541 /* Any other names starting in $ are debugger internal variables. */
543 write_exp_elt_opcode (OP_INTERNALVAR
);
544 write_exp_elt_intern (lookup_internalvar (copy_name (str
) + 1));
545 write_exp_elt_opcode (OP_INTERNALVAR
);
548 write_exp_elt_opcode (OP_LAST
);
549 write_exp_elt_longcst ((LONGEST
) i
);
550 write_exp_elt_opcode (OP_LAST
);
553 write_exp_elt_opcode (OP_REGISTER
);
554 write_exp_elt_longcst (i
);
555 write_exp_elt_opcode (OP_REGISTER
);
560 /* Parse a string that is possibly a namespace / nested class
561 specification, i.e., something of the form A::B::C::x. Input
562 (NAME) is the entire string; LEN is the current valid length; the
563 output is a string, TOKEN, which points to the largest recognized
564 prefix which is a series of namespaces or classes. CLASS_PREFIX is
565 another output, which records whether a nested class spec was
566 recognized (= 1) or a fully qualified variable name was found (=
567 0). ARGPTR is side-effected (if non-NULL) to point to beyond the
568 string recognized and consumed by this routine.
570 The return value is a pointer to the symbol for the base class or
571 variable if found, or NULL if not found. Callers must check this
572 first -- if NULL, the outputs may not be correct.
574 This function is used c-exp.y. This is used specifically to get
575 around HP aCC (and possibly other compilers), which insists on
576 generating names with embedded colons for namespace or nested class
579 (Argument LEN is currently unused. 1997-08-27)
581 Callers must free memory allocated for the output string TOKEN. */
583 static const char coloncolon
[2] = {':',':'};
586 parse_nested_classes_for_hpacc (name
, len
, token
, class_prefix
, argptr
)
593 /* Comment below comes from decode_line_1 which has very similar
594 code, which is called for "break" command parsing. */
596 /* We have what looks like a class or namespace
597 scope specification (A::B), possibly with many
598 levels of namespaces or classes (A::B::C::D).
600 Some versions of the HP ANSI C++ compiler (as also possibly
601 other compilers) generate class/function/member names with
602 embedded double-colons if they are inside namespaces. To
603 handle this, we loop a few times, considering larger and
604 larger prefixes of the string as though they were single
605 symbols. So, if the initially supplied string is
606 A::B::C::D::foo, we have to look up "A", then "A::B",
607 then "A::B::C", then "A::B::C::D", and finally
608 "A::B::C::D::foo" as single, monolithic symbols, because
609 A, B, C or D may be namespaces.
611 Note that namespaces can nest only inside other
612 namespaces, and not inside classes. So we need only
613 consider *prefixes* of the string; there is no need to look up
614 "B::C" separately as a symbol in the previous example. */
618 char * prefix
= NULL
;
620 struct symbol
* sym_class
= NULL
;
621 struct symbol
* sym_var
= NULL
;
624 int colons_found
= 0;
629 /* Check for HP-compiled executable -- in other cases
630 return NULL, and caller must default to standard GDB
633 if (!hp_som_som_object_present
)
634 return (struct symbol
*) NULL
;
638 /* Skip over whitespace and possible global "::" */
639 while (*p
&& (*p
== ' ' || *p
== '\t')) p
++;
640 if (p
[0] == ':' && p
[1] == ':')
642 while (*p
&& (*p
== ' ' || *p
== '\t')) p
++;
646 /* Get to the end of the next namespace or class spec. */
647 /* If we're looking at some non-token, fail immediately */
649 if (!(isalpha (*p
) || *p
== '$' || *p
== '_'))
650 return (struct symbol
*) NULL
;
652 while (*p
&& (isalnum (*p
) || *p
== '$' || *p
== '_')) p
++;
656 /* If we have the start of a template specification,
657 scan right ahead to its end */
658 q
= find_template_name_end (p
);
665 /* Skip over "::" and whitespace for next time around */
666 while (*p
&& (*p
== ' ' || *p
== '\t')) p
++;
667 if (p
[0] == ':' && p
[1] == ':')
669 while (*p
&& (*p
== ' ' || *p
== '\t')) p
++;
671 /* Done with tokens? */
672 if (!*p
|| !(isalpha (*p
) || *p
== '$' || *p
== '_'))
675 tmp
= (char *) alloca (prefix_len
+ end
- start
+ 3);
678 memcpy (tmp
, prefix
, prefix_len
);
679 memcpy (tmp
+ prefix_len
, coloncolon
, 2);
680 memcpy (tmp
+ prefix_len
+ 2, start
, end
- start
);
681 tmp
[prefix_len
+ 2 + end
- start
] = '\000';
685 memcpy (tmp
, start
, end
- start
);
686 tmp
[end
- start
] = '\000';
690 prefix_len
= strlen (prefix
);
692 #if 0 /* DEBUGGING */
693 printf ("Searching for nested class spec: Prefix is %s\n", prefix
);
696 /* See if the prefix we have now is something we know about */
700 /* More tokens to process, so this must be a class/namespace */
701 sym_class
= lookup_symbol (prefix
, 0, STRUCT_NAMESPACE
,
702 0, (struct symtab
**) NULL
);
706 /* No more tokens, so try as a variable first */
707 sym_var
= lookup_symbol (prefix
, 0, VAR_NAMESPACE
,
708 0, (struct symtab
**) NULL
);
709 /* If failed, try as class/namespace */
711 sym_class
= lookup_symbol (prefix
, 0, STRUCT_NAMESPACE
,
712 0, (struct symtab
**) NULL
);
717 (t
= check_typedef (SYMBOL_TYPE (sym_class
)),
718 (TYPE_CODE (t
) == TYPE_CODE_STRUCT
719 || TYPE_CODE (t
) == TYPE_CODE_UNION
))))
721 /* We found a valid token */
722 *token
= (char *) xmalloc (prefix_len
+ 1 );
723 memcpy (*token
, prefix
, prefix_len
);
724 (*token
)[prefix_len
] = '\000';
728 /* No variable or class/namespace found, no more tokens */
730 return (struct symbol
*) NULL
;
733 /* Out of loop, so we must have found a valid token */
740 *argptr
= done
? p
: end
;
742 #if 0 /* DEBUGGING */
743 printf ("Searching for nested class spec: Token is %s, class_prefix %d\n", *token
, *class_prefix
);
746 return sym_var
? sym_var
: sym_class
; /* found */
750 find_template_name_end (p
)
754 int just_seen_right
= 0;
755 int just_seen_colon
= 0;
756 int just_seen_space
= 0;
758 if (!p
|| (*p
!= '<'))
765 case '\'': case '\"':
767 /* In future, may want to allow these?? */
770 depth
++; /* start nested template */
771 if (just_seen_colon
|| just_seen_right
|| just_seen_space
)
772 return 0; /* but not after : or :: or > or space */
775 if (just_seen_colon
|| just_seen_right
)
776 return 0; /* end a (nested?) template */
777 just_seen_right
= 1; /* but not after : or :: */
778 if (--depth
== 0) /* also disallow >>, insist on > > */
779 return ++p
; /* if outermost ended, return */
782 if (just_seen_space
|| (just_seen_colon
> 1))
783 return 0; /* nested class spec coming up */
784 just_seen_colon
++; /* we allow :: but not :::: */
789 if (!((*p
>= 'a' && *p
<= 'z') || /* allow token chars */
790 (*p
>= 'A' && *p
<= 'Z') ||
791 (*p
>= '0' && *p
<= '9') ||
792 (*p
== '_') || (*p
== ',') || /* commas for template args */
793 (*p
== '&') || (*p
== '*') || /* pointer and ref types */
794 (*p
== '(') || (*p
== ')') || /* function types */
795 (*p
== '[') || (*p
== ']') )) /* array types */
810 /* Return a null-terminated temporary copy of the name
811 of a string token. */
817 memcpy (namecopy
, token
.ptr
, token
.length
);
818 namecopy
[token
.length
] = 0;
822 /* Reverse an expression from suffix form (in which it is constructed)
823 to prefix form (in which we can conveniently print or execute it). */
826 prefixify_expression (expr
)
827 register struct expression
*expr
;
830 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expr
->nelts
);
831 register struct expression
*temp
;
832 register int inpos
= expr
->nelts
, outpos
= 0;
834 temp
= (struct expression
*) alloca (len
);
836 /* Copy the original expression into temp. */
837 memcpy (temp
, expr
, len
);
839 prefixify_subexp (temp
, expr
, inpos
, outpos
);
842 /* Return the number of exp_elements in the subexpression of EXPR
843 whose last exp_element is at index ENDPOS - 1 in EXPR. */
846 length_of_subexp (expr
, endpos
)
847 register struct expression
*expr
;
850 register int oplen
= 1;
851 register int args
= 0;
855 error ("?error in length_of_subexp");
857 i
= (int) expr
->elts
[endpos
- 1].opcode
;
863 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
864 oplen
= 5 + BYTES_TO_EXP_ELEM (oplen
+ 1);
887 case OP_F77_UNDETERMINED_ARGLIST
:
889 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
917 case STRUCTOP_STRUCT
:
925 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
926 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
930 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
931 oplen
= (oplen
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
932 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
);
937 args
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
938 args
-= longest_to_int (expr
->elts
[endpos
- 3].longconst
);
944 case TERNOP_SLICE_COUNT
:
949 case MULTI_SUBSCRIPT
:
951 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
954 case BINOP_ASSIGN_MODIFY
:
965 args
= 1 + (i
< (int) BINOP_END
);
970 oplen
+= length_of_subexp (expr
, endpos
- oplen
);
977 /* Copy the subexpression ending just before index INEND in INEXPR
978 into OUTEXPR, starting at index OUTBEG.
979 In the process, convert it from suffix to prefix form. */
982 prefixify_subexp (inexpr
, outexpr
, inend
, outbeg
)
983 register struct expression
*inexpr
;
984 struct expression
*outexpr
;
988 register int oplen
= 1;
989 register int args
= 0;
992 enum exp_opcode opcode
;
994 /* Compute how long the last operation is (in OPLEN),
995 and also how many preceding subexpressions serve as
996 arguments for it (in ARGS). */
998 opcode
= inexpr
->elts
[inend
- 1].opcode
;
1003 oplen
= longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1004 oplen
= 5 + BYTES_TO_EXP_ELEM (oplen
+ 1);
1017 case OP_INTERNALVAR
:
1027 case OP_F77_UNDETERMINED_ARGLIST
:
1029 args
= 1 + longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1055 case STRUCTOP_STRUCT
:
1064 oplen
= longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1065 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
1069 oplen
= longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1070 oplen
= (oplen
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
1071 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
);
1076 args
= longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1077 args
-= longest_to_int (inexpr
->elts
[inend
- 3].longconst
);
1083 case TERNOP_SLICE_COUNT
:
1087 case BINOP_ASSIGN_MODIFY
:
1093 case MULTI_SUBSCRIPT
:
1095 args
= 1 + longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1104 args
= 1 + ((int) opcode
< (int) BINOP_END
);
1107 /* Copy the final operator itself, from the end of the input
1108 to the beginning of the output. */
1110 memcpy (&outexpr
->elts
[outbeg
], &inexpr
->elts
[inend
],
1111 EXP_ELEM_TO_BYTES (oplen
));
1114 /* Find the lengths of the arg subexpressions. */
1115 arglens
= (int *) alloca (args
* sizeof (int));
1116 for (i
= args
- 1; i
>= 0; i
--)
1118 oplen
= length_of_subexp (inexpr
, inend
);
1123 /* Now copy each subexpression, preserving the order of
1124 the subexpressions, but prefixifying each one.
1125 In this loop, inend starts at the beginning of
1126 the expression this level is working on
1127 and marches forward over the arguments.
1128 outbeg does similarly in the output. */
1129 for (i
= 0; i
< args
; i
++)
1133 prefixify_subexp (inexpr
, outexpr
, inend
, outbeg
);
1138 /* This page contains the two entry points to this file. */
1140 /* Read an expression from the string *STRINGPTR points to,
1141 parse it, and return a pointer to a struct expression that we malloc.
1142 Use block BLOCK as the lexical context for variable names;
1143 if BLOCK is zero, use the block of the selected stack frame.
1144 Meanwhile, advance *STRINGPTR to point after the expression,
1145 at the first nonwhite character that is not part of the expression
1146 (possibly a null character).
1148 If COMMA is nonzero, stop if a comma is reached. */
1151 parse_exp_1 (stringptr
, block
, comma
)
1153 struct block
*block
;
1156 struct cleanup
*old_chain
;
1158 lexptr
= *stringptr
;
1161 type_stack_depth
= 0;
1163 comma_terminates
= comma
;
1165 if (lexptr
== 0 || *lexptr
== 0)
1166 error_no_arg ("expression to compute");
1168 old_chain
= make_cleanup ((make_cleanup_func
) free_funcalls
, 0);
1171 expression_context_block
= block
? block
: get_selected_block ();
1173 namecopy
= (char *) alloca (strlen (lexptr
) + 1);
1176 expout
= (struct expression
*)
1177 xmalloc (sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_size
));
1178 expout
->language_defn
= current_language
;
1179 make_cleanup ((make_cleanup_func
) free_current_contents
, &expout
);
1181 if (current_language
->la_parser ())
1182 current_language
->la_error (NULL
);
1184 discard_cleanups (old_chain
);
1186 /* Record the actual number of expression elements, and then
1187 reallocate the expression memory so that we free up any
1190 expout
->nelts
= expout_ptr
;
1191 expout
= (struct expression
*)
1192 xrealloc ((char *) expout
,
1193 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_ptr
));;
1195 /* Convert expression from postfix form as generated by yacc
1196 parser, to a prefix form. */
1198 #ifdef MAINTENANCE_CMDS
1199 if (expressiondebug
)
1200 dump_prefix_expression (expout
, gdb_stdout
,
1201 "before conversion to prefix form");
1202 #endif /* MAINTENANCE_CMDS */
1204 prefixify_expression (expout
);
1206 #ifdef MAINTENANCE_CMDS
1207 if (expressiondebug
)
1208 dump_postfix_expression (expout
, gdb_stdout
,
1209 "after conversion to prefix form");
1210 #endif /* MAINTENANCE_CMDS */
1212 *stringptr
= lexptr
;
1216 /* Parse STRING as an expression, and complain if this fails
1217 to use up all of the contents of STRING. */
1220 parse_expression (string
)
1223 register struct expression
*exp
;
1224 exp
= parse_exp_1 (&string
, 0, 0);
1226 error ("Junk after end of expression.");
1230 /* Stuff for maintaining a stack of types. Currently just used by C, but
1231 probably useful for any language which declares its types "backwards". */
1235 enum type_pieces tp
;
1237 if (type_stack_depth
== type_stack_size
)
1239 type_stack_size
*= 2;
1240 type_stack
= (union type_stack_elt
*)
1241 xrealloc ((char *) type_stack
, type_stack_size
* sizeof (*type_stack
));
1243 type_stack
[type_stack_depth
++].piece
= tp
;
1250 if (type_stack_depth
== type_stack_size
)
1252 type_stack_size
*= 2;
1253 type_stack
= (union type_stack_elt
*)
1254 xrealloc ((char *) type_stack
, type_stack_size
* sizeof (*type_stack
));
1256 type_stack
[type_stack_depth
++].int_val
= n
;
1262 if (type_stack_depth
)
1263 return type_stack
[--type_stack_depth
].piece
;
1270 if (type_stack_depth
)
1271 return type_stack
[--type_stack_depth
].int_val
;
1272 /* "Can't happen". */
1276 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1277 as modified by all the stuff on the stack. */
1279 follow_types (follow_type
)
1280 struct type
*follow_type
;
1284 struct type
*range_type
;
1287 switch (pop_type ())
1293 follow_type
= lookup_pointer_type (follow_type
);
1296 follow_type
= lookup_reference_type (follow_type
);
1299 array_size
= pop_type_int ();
1300 /* FIXME-type-allocation: need a way to free this type when we are
1303 create_range_type ((struct type
*) NULL
,
1304 builtin_type_int
, 0,
1305 array_size
>= 0 ? array_size
- 1 : 0);
1307 create_array_type ((struct type
*) NULL
,
1308 follow_type
, range_type
);
1310 TYPE_ARRAY_UPPER_BOUND_TYPE(follow_type
)
1311 = BOUND_CANNOT_BE_DETERMINED
;
1314 /* FIXME-type-allocation: need a way to free this type when we are
1316 follow_type
= lookup_function_type (follow_type
);
1323 _initialize_parse ()
1325 type_stack_size
= 80;
1326 type_stack_depth
= 0;
1327 type_stack
= (union type_stack_elt
*)
1328 xmalloc (type_stack_size
* sizeof (*type_stack
));
1330 msym_text_symbol_type
=
1331 init_type (TYPE_CODE_FUNC
, 1, 0, "<text variable, no debug info>", NULL
);
1332 TYPE_TARGET_TYPE (msym_text_symbol_type
) = builtin_type_int
;
1333 msym_data_symbol_type
=
1334 init_type (TYPE_CODE_INT
, TARGET_INT_BIT
/ HOST_CHAR_BIT
, 0,
1335 "<data variable, no debug info>", NULL
);
1336 msym_unknown_symbol_type
=
1337 init_type (TYPE_CODE_INT
, 1, 0,
1338 "<variable (not text or data), no debug info>",
1341 #ifdef MAINTENANCE_CMDS
1343 add_set_cmd ("expressiondebug", class_maintenance
, var_zinteger
,
1344 (char *)&expressiondebug
,
1345 "Set expression debugging.\n\
1346 When non-zero, the internal representation of expressions will be printed.",